<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        /* li {
            color: red;
        } */
        /* .red {
            color: red;
        } */
        /* ol li {
            color: red;
        } */
        /* .hobby li {
            color: red;
        } */

        li a {
            color: red;
        }

    </style>
</head>
<body>
    <ul>
        <li>吃饭</li>
        <li>吃饭</li>
        <li>吃饭</li>
    </ul>
    <ol class="hobby">
        <li class="red">吃饭</li>
        <li class="red">吃饭</li>
        <li class="red">
            <a href="#">吃饭</a>
        </li>
    </ol>
</body>
</html>